As is well known in the art, heart failure can be caused by a diverse array of cardiovascular disorders that reduce the efficiency of the myocardium, including ischemic heart disease, coronary artery disease, and a defective or diseased heart valve. Among the noted disorders, ischemic heart disease, which commonly presents as a myocardial infarction, is the leading cause of heart failure.
Indeed, in 2004 alone, the World Health Organization estimated that 12.2% of worldwide deaths occurred as a result of ischemic heart disease. Ischemic heart disease was also deemed the leading cause of death in middle to high income countries and second only to respiratory infections in lower income countries. The Global Burden of Disease: World Health Organization 2004 Update, Geneva (2008). Worldwide more than 3 million people present with a ST elevation myocardial infarction (STEMI) and 4 million people present with a non-ST elevation myocardial infarction (NSTEMI) a year. White, et al., Acute Myocardial Infarction, Lancet 372 (9638), pp. 570-84 (August 2008).
Rates of death from ischemic heart disease have slowed or declined in most high income countries, although cardiovascular disease still accounted for 1 in 3 of all deaths in the USA in 2008. Roger, et al., Executive summary: Heart Disease and Stroke Statistics—2012 update: A report from the American Heart Association, Circulation 125 (1), pp. 188-97 (January 2012).
In contrast, ischemic heart disease is becoming a more common cause of death in the developing world. For example in India, ischemic heart disease had become the leading cause of death by 2004; accounting for 1.46 million deaths (14% of total deaths). Deaths in India due to ischemic heart disease were also expected to double during 1985-2015. Gupta, et al., Epidemiology and Causation of Coronary Heart Disease and Stroke in India, Heart 94 (1), pp. 16-26 (January 2008).
Globally, it is predicted that disability adjusted life years (DALYs) lost to ischemic heart disease will account for 5.5% of total DALYs in 2030, making it the second most important cause of disability (after unipolar depressive disorder), as well as the leading cause of death by this date.
Ischemic heart disease often occurs when myocardial tissue is no longer receiving adequate blood flow. Various methods for treating ischemic heart disease have thus been developed. Such methods include systemic delivery of various pharmacological agents.
Several additional methods for treating ischemic heart disease are directed to re-establishing blood flow to the ischemic area. Such methods include stimulation of angiogenesis and surgical intervention, e.g. bypass surgery or angioplasty. Other methods include the use of lasers to bore holes through the ischemic area(s) to promote blood flow. As one can readily appreciate, there are numerous incumbent risks associated with the noted methods.
A further method for treating ischemic heart disease is the direct delivery of bioactive or pharmacological agents to the ischemic area. Illustrative is the delivery of extracellular matrix (ECM) based compositions directly to cardiovascular tissue disclosed in Co-pending application Ser. No. 13/573,569.
More recently, ventricular assist devices (VADs) have been employed as treatment platforms for various pharmacological therapies, e.g. stem cell administration, which have been developed to treat cardiovascular disorders, including ischemic heart disease. VADs are designed to support (or augment) the function of either the right (RVAD) or left (LVAD) ventricle, or both at once (BiVAD). The type of VAD employed depends primarily on the underlying cardiovascular disorder, and the pulmonary arterial resistance that determines the load on the right ventricle.
Although the direct delivery of bioactive or pharmacological agents; particularly, the ECM based compositions disclosed in Co-pending application Ser. No. 13/573,569, and other treatment therapies employing ventricular assistance have been found effective to treat cardiovascular disorders and, thereby, heart failure, there remains a need to provide even more effective means for treating cardiovascular disorders.
It is therefore an object of the present invention to provide improved compositions and methods for treating damaged or diseased biological tissue; particularly, cardiovascular tissue and, hence, cardiovascular disorders associated therewith.
It is another an object of the present invention to provide ECM based compositions that promote tissue survival, and induce neovascularization and regeneration of damaged cardiovascular tissue.
It is yet another object of the present invention to provide methods for treating cardiovascular disorders that includes administration of an ECM based composition, which, when delivered to damaged biological tissue; particularly, cardiovascular tissue, induces neovascularization, host tissue proliferation, bioremodeling, and regeneration of cardiovascular tissue and associated structures with site-specific structural and functional properties.